Boat



March 8, 1949. P. c. CHRISTIANSEN BOAT 2 Shqets-Sheet 1 Filed March 7, 1945 mmv roa Philzp C. Chrz'sfzansen AT TORNE Y:

M h 8, 1949. P. c. CHRISTIANSEN BOAT 2 Sheets-Sheet '2 Filed March 7, 1945 INVENTOR. Philgv C. Christiansen ATTORNEY? Patented Mar. 8, 1949 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to boats and has for a general object the provision of a boat capable of safe high speed travel and quick and ready maneuvering in shallow waters of lakes and streams.

In carrying out the present invention a power driven air propeller is utilized as a propulsion medium thereby avoiding the under water projection characteristic of water propellers.

Boats heretofore equipped with driving air propellers have not proven entirely satisfactory for various reasons. This is due at least in part to the practice heretofore universally followed of mounting the propeller above the boat and usually over the stern thereof where it develops a 1 reaction thrust tending to unstabilize the boat and to reduce the speed at which the boat can be safely operated or maneuvered. This condition is aggravated by the weight and heighth above water level of the propeller and its mountings.

A more specific object of the present invention is to provide a boat driven by an air propeller in such manner as to avoid the above noted difficulties. This I have accomplished by mounting the propeller in a position ahead of the boat and as low as non-interference with the water will permit, which also permits a much more appealing design to the eye.

Another specific object is to provide a boat so designed as to obtain maximum efficiency from a forwardly mounted air propeller.

Other more specific objects and advantages will appear, expressed or implied, from the following description of an illustrative embodiment of the present invention.

In the accompanying drawings:

Figure l is a view in side elevation of a boat designed and equipped with a forward air propeller in accordance with the present invention.

Fig. 2 is a plan view.

Fig. 3 is a transverse sectional view taken substantially along the line 33 of Fig. 2.

Fig. 4 is a transverse sectional view taken substantially along the line 4-4 of Fig. 2.

The boat selected for illustration is provided with a forward compartment l covered by a deck II and accessible through a pair of hinged hatch doors I2.

The boat is shown driven by an air propeller l3 disposed in advance thereof and as close to the water as is possible without interference therewith. The propeller I3 is keyed or otherwise fixed to the forwardly projecting end of a horizontal drive shaft l4 preferably disposed immediately below the deck I I and journalled in a suitable fitting l5 anchored to the stem l6 of the boat.

The propeller shaft I4 is preferably coupled directly to and driven by a suitable high speed internal combustion engine l'l (small aircraft engine) arranged in the upper part of the compartment ill under the hatch doors l2. The engine shown is an airplane motor of a well known type mounted on a pair of heavy transverse beams l8 which are securely fixed at their opposite ends to side frames [9 of the boat in a manner to stiffen the boat structure. In this connection it will be noted that the side frames l9 are slightly convexly bowed or arched to better sustain-the vibrations incident to engine and propeller action.

The boat shown is shaped to offer minimum interference with the propeller slip stream so as to obtain maximum effectiveness and efficiency from the propeller. For that purpose the cockpit 2%] is contained within the forward portion of a narrow, centrally disposed, elongated housing structure 2i that extends aft from the forward compartment it. The housing structure 2| is longitudinally tapered and terminates at its rear end in a pointed extremity 22 preferably disposed above the water level at the stern of the boat.

The cockpit 28 is separated from the forward compartment IE by a suitable bulkhead 23, and is preferably closed by a suitable windshield 24, cover panels 25 and 2B, and a rear window 21', all preferably for-med of a transparent plastic, such as Plexiglas. The window 21 and cover panels 25 and 26 are preferably arched to conform to the arched roof 28 of the housing 2|, and the cover panels 25 and 25 are preferably slidably mounted in suitable guides 29 to afford access to the cockpit.

The housing structure 25 is flanked by outwardly sloping side decks 30 disposed below the level of the forward deck H. At each side of the structure 21 the forward compartment 10 is closed by a bulkhead 3i having a rearwardly sloping portion 32 which is joined to the forward end of the adjacent side deck 30, and each side deck 30 slopes rearwardly therefrom. The rear extremities of the side decks 30 are structurally joined to two rearward extensions 33 of the boat bottom 34 to form substantially fiat stabilizing appendages 35 disposed at opposite sides of and below the extremity 22 of the housing structure 2|.

Except for the extensions 33, the bottom 34 of the boat is of conventional design preferably equipped with a conventional step for high speed travel and easy maneuverability.

Various changes may be made in the embodiment of the invention hereinabove specifically 3 described without departing from or sacrificing the advantages of the invention as defined in the appended claim.

I claim:

A boat having a forward compartment, a propeller shaft extending from said compartment through and beyond the stem of said boat, an air propeller fixed to and driven by the forward projecting end of said shaft, a motor for driving said shaft, means for supporting said motor in elevated position Within said compartment, said motor support comprising a transverse beam connecting the side walls of said compartment to stifien the same and thereby better sustain vibrations incident to engine and propeller action, a compartment extending rearwardlyfrom said first named compartment, and rearwardly sloping side decks flanking said last named compartment and cooperating with the boat bottom to form laterally 4 spaced stabilizing appendages at the stern of the boat.

PHILIP C. CHRISTIANSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

